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| PERES II multi-sensor Bridge Deck Condition detecting system |
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GPR systems use electromagnetic radiation at microwaves frequencies (anywhere in the range from 100 MHz to 10.0 GHz) to ascertain properties of subsurface features. One of the useful properties of microwaves is that they travel through many dielectric materials. Microwave propagation characteristics, in particular velocity and acceleration, vary depending on the properties of the dielectric material. Concrete is a dielectric material that allows transmission of radar waves. Changes in the velocity of propagation at interfaces between different materials can be observed using equipment that transmits and receives precisely controlled microwave pulses, i.e. radar systems.
The PERES II is a specialized ground penetrating radar system (GPR), consisting of hardware specifically designed for concrete bridge deck inspection and material investigation. (Right figure) (USA) designed and built the PERES II system for the US Federal Highway Administration as part of a multi year effort to bring imaging radar technology into the realm of bridge deck inspections.
The PERES II prototype was built in an effort to meet three specific performance goals:
1. Detect defects, at elevations ranging from the top reinforcing steel mat to the deck midsection, with a reliability of 90 percent through asphalt and concrete overlays.
2. Image delaminations in a bridge with a concrete or asphalt overlay with a spatial accuracy equal to the accuracy of the chain drag method applied on a bare concrete deck.
3. Detect defects at the elevation of the bottom reinforcing steel materials.
Dr. Huston’s team has already conducted several lab tests for the different concrete slabs and two field tests on the bridge decks in Virginia, USA. The tests’ results were encouraging and useful for concrete bridge deck condition diagnosis, maintenance and replacement. The figure on the right shows sample of test results.
Currently the UVM CAPSEL team is in the process of upgrading the PERES II to a multi-sensor system by integrated different detection systems with the current PERES system in order to get more accurate bridge deck condition data, and establish three dimensional deck images for further bridge maintenance work.
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PERES II system on Carter Creek Bridge, Dumfries, VA, USA on Oct. 2006
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Test slab with air gap
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PERES Dara processed using LLNL software
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3-D PERES data shown using Slicer Dicer software
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H2 Storage - Self-Sealing Pressure Vessels |
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Self-Sealing Pressure Vessels project focused on using self-sealing technologies to improve the safety and performance of hydrogen fuel storage and transportation systems. The renewable and pollution free characteristics of hydrogen make it a prime candidate fuel of the future. Nonetheless, the generation, storage, transportation, and distribution of hydrogen poses significant technological hurdles. To approach the energy densities currently available to the public in the form of gasoline, gaseous hydrogen must be liquefied at cryogenic temperatures, highly compressed, stored using a physical medium such as metal hydrides, or some combination of the three. Limitations in sealing and insulating liquefied hydrogen, and the lack of viable reversible metal hydride storage systems, presently make high-pressure hydrogen the most viable solution.
Storing sufficient hydrogen fuel on a vehicle to meet the Department of Energy target for driving ranges of 200km-600km requires storage pressure of 35 – 70 MPa. These pressures are at the upper limit of modern pressure vessel technology. Leaks are problematic in any sort of liquid storage system. Numerous technologies are available for self-sealing low pressure applications, such as fuel tanks on military aircraft, or stop-leak additives for automobile radiators. High-pressure systems pose special challenges including a higher occurrence of leaks and higher consequences in the event of pressure vessel failure. High-pressure hydrogen is particularly challenging due the difficulty in sealing the low atomic weight gas, the extreme pressures involved, embrittlement of storage materials, and the broad volumetric ratios over which hydrogen is combustible.
This project completed an exhaustive background research into what the current state of the art is in self sealing pressure vessel technologies. A novel lab setup was created for the evaluation of current self sealing products and the development of future technologies. Self sealing experiments can be comprehensively monitored and characterized using advanced and highly sensitive equipment. The collected data is doubly beneficial in that it can be used to develop current self sealing methods as well as provide a base of knowledge for future NDE of self sealing pressure vessels in use.
The UVM CAP team built the test bed, tested the different materials. Meanwhile the pressure vessel was also monitored using a Physical Acoustics Corp. Non-destructive Testing system and the pressure transducer. Successful self sealing tests had virtually no pressure loss during and after puncture. Test bed and monitoring station is shown in below.
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Self Sealing Pressure Vessel Test Bed
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Pneumatic Manifold and Monitoring Station
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| Self-healing Wire and Cable Insulation |
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Self-healing cable apparatus and methods are disclosed. The cable has a central core surrounded by an adaptive cover that can extend over the entire length of the cable or just one or more portions of the cable. The adaptive cover includes a protective layer having an initial damage resistance, and a reactive layer. When the cable is subjected to a localized damaging force, the reactive layer responds by creating a corresponding localized self-healed region. The self-healed region provides the cable with enhanced damage resistance as compared to the cable's initial damage resistance. Embodiments of the invention utilize conventional epoxies or foaming materials in the reactive layer that are released to form the self-healed region when the damaging force reaches the reactive layer.
United States Patent No. 7,302,145, Nov. 27, 2007
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| Lordosimeter |
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Back pain is a serious health problem. It has long been thought that posture plays an important role in the causes of lower back pain. For example, it is generally believed that sitting up straight will reduce the probability that you will experience lower back pain. However, it has been difficult to determine how important posture is in causing or preventing back pain. The aim of the research is to develop a device that will monitor posture by measuring and recording lower back curvature.
Subjects will wear a back curvature measuring device consisting of a sensor in a neoprene corset and a small unit for monitoring and recording the sensor output. This device can measure the curvature of your back and can be set to alarm if the subject’s curvature exceeds certain limits. The alarm will be a vibration typical of telephone pagers.
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Subject wearing the device in the straight right position |
Subject wearing the device in the slump position |
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Typical Data with Feedback Buzzer On May 19th 2008, Belt Office Chair 1 hour
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| MEMS Gyro |
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This project is to develop Microelectromechanical (MEMS) based Control Moment Gyros (CMG) for attitude control in small satellites. Small satellites have become useful and intelligent spacecrafts with sophisticated attitude control and determination systems. However, near future missions will require a higher degree of agility and better efficiency. CMG’s are an ideal candidate technology with a unique capability to efficiently produce large torques and angular momentum with a small power consumption and savings in mass. Both the large scale and current MEMS devices will be researched and compared to see the applicability of MEMS gyros for use in controlling the orientation of small satellites. Currently MEMS gyros use the Coriolis affect for sensing, we will be looking into the possibility of inverting the mechanics of these devices to produce a torques that could then be used to control orientation.
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